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1 Introduction and Historical Background
Pages 7-16

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From page 7...
... were also capable of producing a significant uncataloged population of debris, and could have already done so.2 The NASA orbital debris program began at JSC with a very small budget of $70,000 3 provided by the NASA Headquarters Advanced Program Office with the initial goals of characterizing the hazard to spacecraft and rec ommending mitigation standards that would minimize the growth of the orbital debris environment. 4 During the program's first few years it quickly established -- by examining returned spacecraft surfaces and using ground telescopes -- that the hazard from debris smaller than about 1 cm had already exceeded the meteoroid hazard in some altitudes below 2,000 km.
From page 8...
... in 1987. By 1991, NASA had also met with space agencies in the USSR, Japan, and China, where each major space agency quickly and informally agreed to the concept of operational procedures for minimizing the possibility of future explosions in orbit.8 These multilateral meetings led to the formal establishment of the Inter-Agency Space Debris Coordination Committee (IADC)
From page 9...
... : • SSTRATCOM: Headquartered at Offutt Air Force Base near Omaha, Nebraska, and one of ten U unified commands in the DOD, USSTRATCOM is responsible for the nation's nuclear command, space operations, global strike, DOD information operations, and global missile defense, among other duties.1 o The Joint Space Operations Center (JSpOC) : Within USSTRATCOM, JSpOC is in charge of detecting, tracking, and identifying man-made objects in Earth orbit.2 When an object can be identified with a particular launch but is not a classified military satellite, it appears in the U.S.
From page 10...
... Yet although the orbital debris mitigation guidelines developed by NASA were gaining wider acceptance by the space community, an increasing number of studies, both national and international, were coming to the conclusion that even absolute compliance with the 25-year rule would be insufficient to prevent the debris population present below 2,000 km (LEO) from continuing to increase as a result of random collisions involving non-operational intact debris.17 These studies concluded that the rate of collisions had already reached the point that debris would 13 NASA, Process for Limiting Orbital Debris, NASA-STD 8719.14 (Change 4)
From page 11...
... FIGURE 1.2.1 The International Space Station's orbit (green) and the debris ring (red)
From page 12...
... MMOD models are developed to contribute to studies and analyses that support not only internal missions but also a significant number of interagency delib erations within the United States and meaningful dialogs internationally. Developed by NASA's Orbital Debris and Program Office, Hypervelocity Impact Test Facility, and Meteoroid Environment Office, the models developed focus on protecting spacecraft, the environment, and people on Earth.
From page 13...
... As a result, capability has been lost and analysis efforts delayed. For example, during 2002 and 2003, the office permanently terminated operations of its Orbital Debris Observatory located in Cloudcroft, New Mexico, shut down the ODPO website for 2 years, and delayed model upgrades that would include debris shape, definition of the debris population at low inclinations, modeling of solid rocket motor aluminum oxide ejecta, and studies to assess the long-term envi ronmental impact of various mitigation measures.
From page 14...
... SOURCE: Courtesy of NASA, "Monthly Number of Objects in Earth Orbit by Object Type," Orbital Debris Quarterly News, Vol. 15, Issue 1, NASA, January 2011, p.
From page 15...
... The scientific community outside NASA has been gathering data that can be used to help update meteoroid models: • Radar observations of meteors have continued to be made outside the United States; • Meteoroid "dust" was captured both in the stratosphere and in space and returned to Earth for analysis with the purpose of understanding dust from comets; • Spacecraft surfaces that were examined for orbital debris impacts were also examined for meteoroid impacts; and • The Max Plank Institute included a cosmic dust detector on the Cassini spacecraft to Saturn, as well as on the Galileo and Ulysses mission, providing data on the dust environment at very small sizes in the outer solar system to complement earlier measurements by Pioneer.29 Of additional importance, at least two spacecraft failures were believed to be associated with high meteor stream activity, even though current meteoroid models predicted no failures during any high meteor stream activi ty.30 Past measurements of the meteoroid flux in all meteor showers had consistently measured an absence of meteoroids with decreasing size,31 so that the predicted impact rate on satellites during meteor showers was many orders of magnitudes lower than required to be consistent with those two failures.
From page 16...
... The MEO is NASA's technical lead for defining the meteoroid environment using radar and optical measurements, performing data analysis, and developing models that can be used together with test results from the HITF at JSC. In the past 6 years, the MEO has improved models describing meteor streams and storms and regularly provides forecasts.


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